avfilter/audio: use av_mallocz_array()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/audio.c

@@ -124,9 +124,9 @@ AVFilterBufferRef* avfilter_get_audio_buffer_ref_from_arrays_channels(uint8_t **
     samples->linesize[0] = samplesref->linesize[0] = linesize;
 
     if (planes > FF_ARRAY_ELEMS(samples->data)) {
-        samples->   extended_data = av_mallocz(sizeof(*samples->extended_data) *
+        samples->   extended_data = av_mallocz_array(sizeof(*samples->extended_data),
                                                planes);
-        samplesref->extended_data = av_mallocz(sizeof(*samplesref->extended_data) *
+        samplesref->extended_data = av_mallocz_array(sizeof(*samplesref->extended_data),
                                                planes);
 
         if (!samples->extended_data || !samplesref->extended_data)